Part Finder (Multi Level)$29.99
The part finder are an search tool for car, moto, printer, phone, etc... It allow create select box are multi level. If your product are cart, you can setup with many type easy: Make, Model, Year, Engine; Year, Mode, Make; etc
Configurable Swatches will help you improve display product configurable instead of display default (select box) of magento.
Compare Product Plus$9.99
Compare Product Plus support ajax, quick view compare. Also, you can allow/disallow guest usage, etc...
Custom Options Templates$29.99
Custom options templates allow you create template and assign custom option for product. You will save time if use it.
Hide Price (Call For Price)$9.99
You can hide price and add to cart button for one or many product with this extension. It allow you replace price by text(call for price, get quote price, etc..) and link.